Flow controller



A. W. FETT FLOW CONTROLLER Oct. 2, 1951 6 Sheets-Sheet l Filed April 10, 1946 INVENTOR. ggf/#eff au Pe ff A ORNEY A. W. PETT FLOW CONTROLLER Oct. 2, 1951 6 Sheets-Sheet 2 Filed April 10, 1946 0 5 w vm... l. *A

Mii 77 INVENTOR. Uff/ed w. P@ ff 1%/ (607 A oeh/EY Oct. 2, 1951 A, w, PETT 2,570,152

FLow CONTROLLER' Filed April 10, 1946 6 Sheets-Sheet 3 IN VEN TOR.

Oct. 2, 1951 A. w. FETT 2,570,152

FLOW CONTROLLER Filed April 10, 1946 6 Sheets-Sheet -4 O j 50 8 68 V DIFFERENTIAL A111 1b cms: vnLvE 4% '""7 ser-rum. 74. 72 75 68A 76 DIFFERENTIAL Alr. To oPlN VALVE 4% '00% SETTING IN V EN TOR.

A TTORNE Y Oct. 2, 1951 A. w. PETT 2,570,152

FLOW CONTROLLER Filed April 10, 1946 6 Sheets-Sheet 6 PERCENT CAM LIFT 9 1o 5o o PERCENT 4o VALVE L FT l 0 s y 152 web I loa INVENTOR. y/frea W. Pe z Patented Oct. 2, 1951 UNITED f STATES PATENT OFFICE FLow coN'raoLLaa Alfred W. Pett, Warwick, R. I.

Application April 1o, 194s, semi No. se1,1so

l 20 Claims.

This invention relates to control apparatus for governing the flow of fluids through closed conduits, pipe lines and the like, and particularly it relates to control apparatus for so regulating such fluid flow as to attain a constant output or rate of discharge from such a conduit.

Where a fluid such as a liquid or a gas is to be transmitted through a closed conduit or pipe line from the supply end thereof to the discharge or consumption end thereof, the iluid must, of course, be under a relative pressure head |atthe supply end so as to induce the desired flow through the line toward and to the 'discharge end. Under constant conditions of supply pressure and discharge pressure in a particular section of pipe line or conduit, the output would be constant, but in practice such constant characteristics in the dow-governing or controlling factors can be attained in but rare instances. In my copending applications, Serial No. 634,521, filed December 12, 1945, now abandoned, and Serial No. 540,865, filed June 1'7, 1944, now/Patent No. 2,399,938, issued May 7, 1946, flow control apparatus has been disclosed and claimed which enables flow of fluids in a pipe line or the like to be governed by means that are responsive to the variable factors that control the flow or output in such a pipe line and an important object of the present invention is to simplify the application of such apparatus to different kinds, types and designs of valve devices.

Further and more specific objects of the invention are to enable flow-calculating and powercontrolling elements of such an apparatus to be constructed as a separate or individual unit adapted to be mounted on and operatively associated with any conventional type of power operated valve, and accomplish this result in such a manner as to enable different flow scales to be utilized as required. More specically it is an object of the invention to enable either linear or parabolic w' scales to be utilized in such an apn 'Another object is-to enable such a flow-control -and"-power-controlling unit to sense the position of the valve member of such a valve in such a way as to translate such position into a mechanical representation of the effective valve orifice, and to enable `this to be accomplished by means including a. replaceable cam that serves to adapt the unit to valves having different strokes and forms of valve member.

In the practical application or use of constantflow valve means of the kind to which this in- 2 vention pertains, the constant flow control means is often utilized as a secondary control means that is variably adjusted under the dominating governing action of a primary control device that is responsive to the ultimate condition which is to be controlled by the system as a whole. As an example, a temperature responsive primary control device may be associated with a room, or a liquid storage tank to measure the temperature thereof, and such room or tank may be heated 4by a heating fluid that flows to the room or tank through a constant flow control valve means. If the setting of the constant flow control valve means happens to be such that the temperature in the room or tank. varies beyond the desired range, the primary control device, which in this instance may take the form of a thermostat, exercises its control over .the constant flow control valve means so as to adjust the constant throughput of the valve in accordance with the detected variation in the primary control condition as represented by the room or tank temperature. In other instances the primary control condition may constitute a liquid level or a pressure level or condition, and hence the nature of the primary control device associated With a, constant flow control means may take many different forms.

In view of the foregoing it is a, further object of the present invention to provide a constant flow control means that is particularly adapted for such association with. a primary control device, and a related object is to provide such a constant flow control means that has a wide range of control operation, thereby to adapt the same for convenient use with a wide variety of primary control devices.

Other and further objects of the present invention will be apparent from the following description and claims and yare illustrated in the accompanying drawings-which..by way of illustration show preferred embodiments and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodimentsmf the invention embodying the same orequivalent principles may be used and structural changes may be made as desired by those skilled in the art Without departing from the present invention and the purview of the appended claims.

In the drawings:

Fig. l is a perspective view showing control apparatus embodying the features of the invention;

Fig. 2 is a perspective view of the front of the computing and power control unit;

and Power control means as employed in the structure of Figs. l to '7 where the valve is spring urged toward open position andis moved toward closed position by power such as pressure air;

Fig. 9 is a schematic view of the computing and power control means such as would be employed where the valve is spring urged toward closed position and is moved toward open position by power such as pressure air;

Fig. is a schematic view of the manner in which the lever system is connected where the square root of the pressure differential is to bev entered into the ow computing mechanism t0 thereby afford control according to a linear flow scale;

Fig. 1l is a schematic view of the manner in which the lever system is connected where the fourth root of the pressure differential is to be entered into the flow computing mechanism to thereby afford control according to a parabolic flow scale; and

Fig. 12 is a diagrammatic view illustrating the manner in which the translating cam is developed for any particular valve design and valve stroke.

In the form chosen for disclosure in Figs. 1 to 8 -of the drawings the invention is embodied in a flow control apparatus comprising a ilow-calculating and power control unit I0 mounted on and operatively associated with a conventional power operated valve unit I I to produce an acl-- .as to be readily adapted for operative association with different sizes and types of valves as well as for operation with different flow scales such as a linear flow scale or a parabolic ow scale. The valve I2 as shown in Fig. 6, has a valve casing I3 having inlet and outlet ends I4 and I5 into which inlet and outlet sections ISA and IEB of a pipe line may be threaded, and generally diagonally of and within the valve casing I3 a division wall I1 is provided for cooperation with a valve member I8 in controlling flow of fluid through the casing I3. The division wall I1 has an opening therein in which a valve seat bushing or member I9 is mounted, and in the form of the invention disclosed in Figs. 1 to 8, the valve member I8 is so related to the valve seat i9 that when the valve is in its upper position, and valve opening 28 in the bushing I9 is open to the maximum, andwhen the valve is to be closed the valve member I8 is moved downwardly. Such movement of the valve member I8 is attained through vertical or longitudinal movement of a 'valve stem 25 that extends upwardly from the valve member I8 and through a. conventional packing gland formed in a mounting boss 21 on the top of the valve housing I3.

The mounting boss 21 has an externally threaded portion formed thereon about the packing gland, and the transverse member 30 of a yoke 3| is mounted on the threaded upper portion of the boss 21 and is held in place by a lock nut 32 threaded onto the boss 21.

The yoke 3|, as herein shown, serves'as a suD- port for the means that actuate and control the position ofthe valve member I8, and in the present instance the valve actuating means 33I are disposed at the upper end of the two spaced and detachably mounted arms 3|A vand 3IB of the yoke 3|. -While it will be understood that such valve actuating means 33 may take many different Iorms and 4may be arranged to utilize many different kinds of operating power, the present embodiment of the invention employs pressure fluid operated actuating means 33 that are operated by a pressure fluid such as air.

Thus, as shown in Figs. 1 and 6 of the drawings,

the arms 3|A and 3IB are formed as integral downward extensions of the side walls of an inverted pan-shaped member or housing 34 that is supported by the arms 3|A and 3IB so as to be concentric with the valve stem 25, and within the housing 34 an extensible bellows 35 is mounted so as to act between the upper wall of the housing and the upper face of a plate 3'6 that is in turn ilxed on the upper end of the valve stem 25. The plate 36 is urged upwardly by a pair of expansive coil springs 31 that are carried on a cross bar 38 extended between the sides of the yoke 3|. Hence the valve member I8 is urged toward its open position, and by application of a press-ure fluid to the chamber 40 within the bellows 35, the valve member I8 may be forced downwardly toward its closed position.

In accordance with the present invention the flow-computing and power-control unit I0 is so constructed and arranged as to be readily associated with a power operated valve unit of the general character thus afforded, and to this end the unit I0 has a plate-like main frame 45 that may be rigidly secured to the valve unit by means of a pair of rigid mounting arms 48 that are secured by screws 41 to the rear face of the plate 45 and which engage opposite outer faces ofthe arms of the yoke 3f and are secured thereto by screws 48. The mounting plate 45 that is thus adapted to be rigidly mounted on a valve unit serves to support a power-control means 50 -for governing the supply of pressure iluid to the pressure chamber 4|),v and in association with the power control means 50, the plate 45 supports computing means, as will hereinafter be described in detail, that are responsive conjointly to the effective valve opening and instantaneous pressure dierential across the valve opening to govern the power control means 50 and thereby cause regulation of flow through the valve at a predetermined adjustably set value.

The power vcontrol means 5|) as herein shown are of the pneumatic relayitype and may be of conventional construction wherein a constant pressure supply oa pressure iluid such as compressed air is connected by a supply pipe 5| to a relay valve mechanism 52 which is secured on the forward face of the plate 45 by screws 52A, and the output of the relay valve mechanism 52 is transmitted to the pressure chamber 40 by a pipe connection 53. The output of the relay valve mechanism is controlled and varied by a vent nozzle 55and a cooperating flapper valve 56, and the nozzle 55 may, if desired, be mounted on bellows 54 in the manner and for the purposeI disclosed in my prior Patent No. 2,331,799, patented October l2, 1943. It may also be noted that the relay valve mechanism 52 may beni Patent No. 2,331,799.` The ilapper valve 58 is pivoted intermediate its ends on a horizontal pivot stud 51 extended from a vertical 'plate 58 mounted in an upwardly extending relation onthe forward face of the casing of the relay valve mechanism 52 by screws 59. 'A spring 60 acts on the napper valve 55 to urge the same toward the nozzle 55, and-the fiapper valve 56 is moved away from the nozzle 55, or in an opening direction, by the calculating means as will now be described. As will hereinafter become apparent, the relationshipof the apper valve 55 to the calculating means determines the value or quantity of the constant flow that is to be maintainedthrough the valve I3, and means is therefore provided for adjusting this relationship, as will hereinafter be described in detail.

Considering the desired constant flow that is'to be maintained as being a selected percentage of the rated maximum flow for the valve I3, the relationship of the calculating means to the napper valve 56 is first set or adjusted according to a percentage flow scale as will hereinafter be apparent, and the calculating means included in the unit lil are then operative to so control the iiapper valve 56 that the valve member I8 is adjusted and readjusted as required to establish and maintain the percentage flow for which the mechanism has been set. Such governing or calculating means are so constructed and arranged as to be responsive to those ultimate factors that tend to vary and control the flow through the valve I3, such factors being the effective opening or area, of the valve opening and the differential pressure that is effective across such valve opening.

Considered broadly, the means that are thus effective to control the flapper valve 56 constitute means for solving mechanically the equation of flow through an orifice or restriction in a pipe line, and for applying the results of such solution t0 the flapper valve 56 in such a way as to vary i i to the effective area of such orifice times the .square root of the pressure differential across such orifice, and it is this formula or relationship that is solved and applied to the flapper valve 56.

In the attainment of such operation, the pressure differential effective across the valve orifice is measured in such a manner as t0 afford a mechanical or positional representation of such differential, and such representation of the differential is applied to a ,primary calculating means which is operable to compute a predetermined root of the differential, such as the square root or the four root thereof, and the function of the differential that is thus obtained is mechanically or positionally represented in such a way that it may be entered as a factor into a second calculating means that serves to multiply such function of the differential by another factor representing the effective opening at the valve orifice 20. The factor that is representative of the effective valve opening is determined by the position of' the valve member I 8 and the valve stem 25, and such position is translated into a mechanical representation of 6 nism 85, mounted on the rear face of the plate 45 as shown in Fig. 4, and adapted to be operatively associated with the valve stem 25.

The particular form of the invention illustrated in Figs. 1 to 7 and 10 of the drawings is adapted for operation in accordance with a linear flow scale, and the primary or first calculating means is arranged to compute the square root of the differential exhibited across the` valve orice, but as will hereinafter become apparent, this first calculating means is so arranged and is so related to the other or related elements of the structure that means for calculating the fourth root of the differential may be readily substituted where operation according to a parabolic flow scale is desired. Thus, as will be evident in the schematic illustration of Fig. 10, and also in Fig. 2, the first calculating or root extracting means comprises a bell crank lever 58, having arms 58A and 58B, pivoted on a horizontal pivot 68 fixed on the forward end of a stud 10 extended forwardly from the front face of the plate 45. The angular relationship between the arms 68A and 68B is such that when the arm 68A is disposed at an angle of ten degrees Ibelow a horizontal line 'II passing through the pivot 69, the arm 58B will be disposed twenty degrees below the line II and on the other side of the pivot 69. With this arrangement the differential may be applied as movement to the arm 58A to rock the bell crank 68 in such a manner that the vertical position of the end of the arm 58B represents the square root of the differential. Thus a relatively long link 'I2 is pivoted at 'I3 to the end of the arm 68A, and is extended generally horizontally to a pivot 'I4 that is movable horizontally in a manner to be disclosed presently to represent the differential that is "detected across the valve orifice. The scale of movement of the pivot point 14 is represented in Fig. 10 as between four percent and one hundred` percent of the differential since it is not contemplated that the valve mechanism will be called upon to function automatically below four percent of the maximum, and moreover, where a calculating lever 68 is to be employed for extracting the square root of the diff'erential, the power required to rock the lever 58 in the lower differential range would be excessive.

As the pivot 'I4 is moved to the right in Fig. l0, the link 'I2 acts to rock the lever 38 in a counterclockwise direction from the full line position thereof toward the dotted lineposition thereof, and in the course of such rocking movement of the lever 68 the vertical movement or position of the end of the arm 68B constitutes at all times a representation of the square root of the differential. The representation that is thus afforded ofthe square root of the differential is transmitted to a generally vertical link l5 that is pivoted at its lower end by a pivot 16 to the end of the arm 68B, and the upper end of the link l5 is connected by a pivot 'Il to one end of a bell cran:

18. The bell crank I8 is pivoted on a pivot pin 'I9 has relatively long arms 18A and 18B, and it is tothe arm 18B that the link I5 is pivoted. It will be observed in the movement of the pivot 14 along its scale from four to one-hundred percent of the differential, the lever 68 is rocked through forty degrees of angular movement so that the arm 68B moves from twenty degrees below the line 1I to twenty degrees above the line 1I, and the length of the link 'I5 and the length of the arm 18B are such that a generally similar range of movement is imparted to the pivot ll. In other words, the arrangement is auch that when 'When the lever 68 is in the full line position of Fig. 10. the position of the pivot 16 is representative of the square root of a `four percent differential. which is equal to twenty percent of the square root of the full one-hundred percent differential, and the arm 18A of the lever 18 is so related to the arm 18B that when these parts are positioned in the full line relation of Fig. 18, a pin 82 at the end of the arm 18A will be positioned to represent twenty percent of the square root of the full orone-hundred percent differential. Thus, by taking a location of the pin 52 on the horizontal line 8| as zero on such a scale. and considering the full angular range of the arm 18B between its full and dotted line positions as being eighty percent of amount of angular movement that would be required to traverse Athe full one-hundred percent on such a scale, -the arm 18A is so related to the arm 18B that when the arm 18 is in its full line position, the arm will be disposed at an angle A below the line 8| which is equal to one-fourth of the angle between the full line and horizontal positions of the arm 18B. Hence when the arm 18B is moved I to its dotted lin position, the pin 82 will be disposed in a position representative of one-hundred percent of the square root of the full differential. With this arrangement the intermediate positions of the pin 82 will be on a linear scale so that the pin 82 will throughout such range of movement constitute a mechanical representation of the square root of the full or onehundred percent differential. Any backlash in the various pivotal connections is taken up by a spring 84 acting on the arm 18A to urge the same in a downward direction.

The -mechanical representation that is thus afforded by the position of the pin 82 constitutes one factor that is utilized in solving the equation of flow, for this mechanical representation is at all times equal to the square root of the percentage of the full or maximum differential. 'I'he other factor that is to be entered into the solution of the equation of flow is the percentage of the effective valve opening, and these two factors are applied to a multiplying lever 85 that is pivoted intermediate its ends on a pivot pin 86. The pivot pin 86 is supported on a carrier 81 that is in the present case in the form of a lever disposed on the rear face of the mounting plate l and pivoted near the lower edge thereof on a pivot pin 88. The lever 81 extends from the bottom of the plate substantially to the top thereof. and the pin 83 is mounted in the lever 81 and is extended forwardly through a slot-88 formed in. the plate45so that the multiplying lever 85 is disposed forwardly of the forward face of the plate Ei Thusthe -pivot 88 of ,the multiplying lever. 85 may be moved in-a generallyhorizontaldirection by rocking movement -of the lever 81, and it is by such rocking movement of the lever 81 that the factor that represents the percontage of effective valve opening is entered into the multiplying operation. The other factor, that is the square root of the percentage of the effective differential is entered into the multiplying'operation by having the pin 82 bear upon the straight lower edge of the multiplying lever Il, as will be evident in Fils. l. '7 and 8 and hence 8 the angularity of the multiplying lever may bechanged either by pivotal movement of the lever 18 or by horizontal shifting movement of the pivot pin 88 of the multiplying lever 85. The pin.82 is so related to the multiplying lever 85 that the point of engagement between the pin 82 and the lever 85 is at all times located to the right of the pivot 86 and the result of the multiplying operation that is effected by the lever 85 is manifested by the position of a pin 88 that bears upwardly against the lower edge of the multiplying lever 85 at a point which is at all times located to the left of thepivot 86, although in some cases the pin 88 may move into alignment with the pivot 83.

The pin 88 ismounted on the right hand end of a transmitting lever 8| that is supported intermediate its end on a pivot 82. and the other or left hand end of the transmitting lever 8 vhas a pin 88 thereon that bears against the lower face of the right hand end of the flapper valve 56. A spring 88 acting on the lever 8| serves to urge the left hand end of the lever 8| downwardly, thereby to maintain the pin 88 in engagement with the multiplying lever 85, and this in turn holds the right hand end of the multiplying lever 85 downwardly against the pin 82. Thus the result of the lcalculating operation, as it is exhibited or manifested in the position of the pin 88 is transmitted through the lever 8| and the' pin 88 to the fiapper valve 56 and when the pin 83 is moved upwardly, the flapper valve 56 is moved away .from the nozzle 55 against the normal clos.

ing action of the spring 68 that will be clearly apparent in Figs. 2 and 8 of the drawings.

When the present device is to be set so as to maintain any desiredpercentageof flow. the action of the calculating means upon ilapper valve 56 must be modified so that the normal position of ilapper valve 56 with respect to the nozzle 55 will be maintained when the calculated flow is equal to the desired flow, and when this adjustment is attained, the calculating means will disturb the normal relationship of the flapper valve 56 when the computed flow differs from the desired flow.

Such adjustment is effected by mounting the pivot pin 82 for substantially vertical adjustment, and this is accomplished by supporting the pivot pin 82 on one arm 85A of a bell crank 85, this bell crank being pivoted on a pivot stud 86 that is extended in a rearward direction from the upper left hand portion of the mounting plate 58. A spring 81 acting on the lower end of the arm 85 urges the bell crank 85 in a counterclockwise direction so as to tend to lift the bell crank arm 85A and the pivot pin 82 in an upward direction, and the adiusting action on the bell crank 85 is attained through means including a vertical adjusting link 88 that is pivoted at a -pivot 88 on the arm 85A of the bell crank.4 The means for applying adjusting movement to the link 88 will be described in detail hereinafter.

In order that the adjustment for which the `apparatus 4'is set may be visually indicated, a

pointer |88 vis mounted on a pivot stud |8| that extends forwardly from the plate 45, and the end |88A of the pointer |88 is arranged to move along anappropriate scale |82 formed on a flange |88 of a plate |84 that is secured by screws |85 to the plate 45 adjacent the right hand end thereof. The pointer 88 is operated from the arm 85A of the bell crank 85 by a link |86 that is pivoted at its opposite ends to the arm 85A and to the pointer |88. Similarly. a pointer ||8 is mounted on the stud I I, and has theend thereof arranged to move along the scale |62, and the pointer |I0 is connected by the link |I| to the -lever 8| adjacent to the pin 80, and hence the pointer I|0 serves as an indicator to indicate the instantaneous flow through the valve I3.

The rocking movement of the lever 81, Figs. 4 and 6, that is required in order to enter the percentage of effective valve opening into the multiplying operation is effected bythe translating mechanism 85 that is carried on the rear face of the plate 45, and this is accomplished by operatively associating a translating cam II5 with the valve stem 25 and with the lever 81 so that movement of the valve stem will be transmitted to the cam I I5 and will be translated by the cam into movement of the lever 81 that is representative of the percentage of effective valve opening. Thus the cam II5 is mounted at one end of a lever II5 that is pivoted at its other end on a pivot II1 extended rearwardly from the plate 45. The cam I I5 is secured in position by screws ||8 so as to be readily put in place on the lever, and the lever I I6 is biased in an upward direction by a spring IIS. The cam |I5 has a cam edge or surface |20 that is arranged to bear against a cam roller I2| that is mounted on the lever 81. In the present instance, the cam roller I2I is mounted on a short lever |22 that is pivoted at |23 on the lever 81, the cam roller I2I being disposed intermediate the pivot |23 and an ear |24 formed on the other end of the lever |22. An ear |25 is formed on the arm or lever 81 and a headed screw |26 is extended through the ear |24 and is threaded through the ear |25. A

spring |21 surrounds the screw between the two ears |24 and |25 so as to hold the ear |24 against the head I28A of the screw. Thus a finely adjustable relationship between the roller I2I and the lever 81 is afforded. The lever 81 is pivoted or urged in a counterclockwise direction Fig. 4 by a spring |28, and thus the roller I2I is held against the edge |28 of the cam II5.

The movement of the valve stem 25 is transmitted to the lever I I6 and the cam |5 by a connesting means that enables the mechanism to be adapted readily to valves having diiierent structures, and this mechanism is also of such a character to enable the location of the range of movement to be readily adjusted and adapted for diff ferent valves. Thus a loosely mounted transmitting lever |30 is pivoted on the pivot stud I |1 and this lever |30 has a laterally projecting ear |3I formed thereon so as to project forwardly and toward the lever II5. An adjustable screw |32 having a lock nut |33 thereon is extended downwardly through the ear I3I and the lower end of the screw |32 is arranged to engage a rearwardly projecting lug |34 that is formed on the lever ||6. Thus the lever IIS, being urged upwardly by the spring IIS, serves through the ear |34, the screw |32, and the ear I3I, to support the arm |38, and when the valve stem 25 moves downwardly, such movement is transmitted to the lever |30 and through the screw |32 to the lever I I5. In accomplishing this actuation of the lever |30, a cylindrical surface |33 is formed on a screw |31 which in turn projects into a slide block |38 that is slotted so as to embrace the oiset edge of the ear I3 I, and the slide block |38 may be screwed in any position along the lever |30 by tightening of the screw |31. The screw |31 projects in a rearward direction so that the cylindrical portion |30 thereof affords a bearing surface that is disposed beneath a horizontal 10 I lower edge |40 that is afforded on a transmittih plate, |4I. The transmitting plate has an ear-f 42 on its upper edge that is put into position with a threaded portion 25A of the valve stem 25 pro- Jecting through the ear |42. The ear |42 is held in position on the threaded portion 25A of the valve stem by nuts |43 that are threaded on thevalve stem above and below the ear |42. Thus the horizontal edge |40 of transmitting plate |4I moves up and down with the valve stem 25, and the action of the spring I I8 on the levers I I8 and |30 holds the bearing |85 in engagement with the surface |40. Thus the cam I ,5 is moved up and down in accordance with the movements of the valve member I8, and by reason of the form of the cam edge |20 of the cam I I5. such movement of the cam I5 is effective to translate the movements of the valve member into mechanical representations of the percentage of effective valve opening. To aid in adjusting the relationship between the valve stem and the movements of the cam II5 a bracket |44 is mounted on the plate 45 and is provided with a scale |55 which cooperates with an edge or mark on the cam I I5 to indicate Whether or not the vertical range of movement of the cam II5 is of the proper extent and is properly located.

In Fig. 12 of the drawings an enlarged illustration of the cam II5 is shown and the general method of laying out the cam surface |20 is shown. Thus a plurality of lines |54 are provided which are arcuateiy related to the center that is to be afforded by the pivot I I1, these lines |54 being arranged along the scale |55 so that each line |54 indicates a ten per cent increment in the range of movement of the pivot 88 of 'the calculating means. A plurality of other lines I5I are also provided in spaced relation, these lines being radial and being centered upon the axis that will be afforded by the pivot I|1. The lines I5| are arranged along the scale |52 in such a manner that the respective lines |54 are disposed at ten percent increment of the total range of movement or stroke of the valve member that is to be utilized. In other words the scale |52 represents a linear percentage scale of the valve stroke while the scale |55 represents a linear percentage scale of the cam lift or rise that is to be afforded in order to impart the necessary shifting movement to the pin 86 and the multiplying lever 85.

As the next step in calculating the cam form, the value of the effective valve opening :required for each ten percent or scale position of the pivot 86 is determined by calculation according to the flow equation and the flow scale that is to be used, and then from the valve characteristic and stroke of the valve that is to be used, the valve positions required to afford the different effective valve areas are determined. The values thus determined are then plotted on the lines |5| and |54 so as to thereby give the form of the cam surface |20. In Fig. l2, a dotted cam outline |20 is illustrated which is adaptable for use with a particular kind of valve which opens as an incident to upward movement of the valve member I8. In full lines in Fig. 12, a valve outline or surface I20A is illustrated which is adaptable for one form of valve that opens the valve as an incident to downwardly movement of the valve member, as I8.

It has been pointed out hereinbefore that the setting of the desired flow is attained by vertical actuation of the link 88. This setting or adjustment may of course be manual, or may be atl1 tained automatically where a primary control is utilized asa rest control for the present control apparatus. In the present embodiment of -"the invention, means are afforded for either manually or automatically setting Ythe flow that is to beA maintained, and for this purpose a bellows |60 is supported at its lower end on a mounting plate |6|,. that is rigidly secured to the plate 45 so as to project outwardly therefrom near the lower edge thereof. The upper end of the bellows |60 has a pressure plate |62 fixed across the closed upper end wall |62A thereof, and an expansive coil spring |68 is arranged at its lower end to engage the pressure plate |62. The upper end of the springl|68 bears against a top plate |64 that is supported in spaced relation to the plate |6I by bolt and spacer devices |65 so that the spring |68 acts normally to urge the pressure plate |62 downward, thereby to tend to compress the bellows |60. The lower end of the link 98 is pivotally connected to an upstanding ear |86 that is provided on the pressure plate |62 so that by vertical movement of the pressure plate |62,

` the flow setting of the apparatus may be adjusted.

wardly through the plate |6| so that the upper end of the screw |10 may bear against a wear plate |62B fixed on the inner or lower face of the upper end wall |62A of the bellows |68. Through this arrangement, the pressure plate |62 may be adjusted upwardly by the screw |10 and l atrofia:

in such adjustment the spring |63 is of course compressed.

The application of the pressure differential to the pivot 14 and thence through the link 12 to the calculating or root extracting lever 68 may be accomplished by means which also serves to measure and determine such differential, but under some circumstances it `may be desirable or more convenient to locate the expansive elements ofv a'pressure differential measuringmeans remotely or externally with 'respect to the flow control mechanism. In the present embodiment of the invention however a pressure differential measuring device |10 is mounted directly on the plate on the forward face thereof. The pres-I sure differential measuring device |10 comprises a pair of end plates |1| and |12 connected by spacer bolts |13 and rigidly secured to the forward face of the plate 45. Between the plates |`|I and |12 a pair of bellows |14 and |15 are mounted in alignment with a central plate |16 disposed therebetween. The sealed' ends of the bellows |14 and |15 are disposed in locating recesses in opposite faces of the central plate |16, while the other ends of the bellows |14 and |15 are sealed respectively to the end plates |12 and I1 I. A balancing spring |11 surrounds the bellows |15 and acts between plates |1| and |16. The pressure on the down stream or low pressure side of the valve I3 is applied through a connection |18 to theinterior of the bellows |15, such connection being extended through the end plate |1I in a conventional manner. Similarly, a connection |80 from the interior of the bellows |14` is extended from the plate |12, as shown in Fig. '1, and is connected to the pipe section I6A so as to apply the high pressure or up stream pressure in the pipe to the bellows |14. The up stream and down stream pressures are thereby balanced one against the other and the position'of the central plate |12 constitutes a linear representation of the pressure differential exhibited across the orifice of the valve I8. This pressure difierential is applied to the pivot 14 by means including a rigid arm |82 fixed to the central plate |16 and extending longitudinally therefrom as shown in Fig. 1. On the arm |82, a longitudinally adjustable bracket is provided and it is with the bracket |85 that the pivot 14 is associated in the present instance. Thus the mechanical representation of the pressure differential that is afforded by the position of the bracket |85 is applied to the link 12 so as to thereby impart the requisite movements to the calculating lever 56. It will be recognized that the initial position of the lever 68 is important, -and this may readily be adjusted by the adjustment of the bracket |85 along the arm |82. In the course of such adjustment of the initial position of the arm 68, the initial position of the transmitting arm 18 `may be disturbed, and as will be evident in Figs. 2 and 3, the connection of the link 15 to the arm 18B is adjustable in character. Thus the arm 18B has a second arm |80 pivoted thereon as at |8I, and the upper end of the link 15 has its pivot 11 connected to the extended end of the lever |80. The lever has a laterally extending ear |82 formed thereon and a threaded screw |83 is extended downwardly through lthe arm 18B and is threaded through the ear |82. An expansive spring |94 surrounds the screw |83 between the lever arm 18B and the ear |82, and thus by adjustment of the screw |83. the initial position of the lever 18 may readily be adjusted in the event this position has been disturbed by adjustment of the bracket |85.

In practice it has been found desirable to limit the counterclockwise movement of the calculating lever 68 so that such movement will be stopped when the arm 68A has moved to a point that is ten degrees away from the line 1| as shown in full lines in Fig. l0 of the drawings, and for this purpose an adjustable stop |86 Figs. 1 and 10 is provided so as to be disposed in the path of the arm 68B. This insures that the arm68 will .be unable to reach a point where the power available in the differential measuring device will be insufficient to move the lever 68 in a counterclockwise direction.

It will be recognized that in the embodiment of the invention shown in Figs. 1 to 8 and 10 the invention has been applied to a power operated valve unit wherein the valve is normally urged toward open position and has air pressure or other pressure applied thereto to close the valve. The control apparatus of the present invention may however be readily changed so as to serve as a control for a valve that is normally spring urged toward closed position and has air pressure or other pressure applied thereto in order to produce opening movement of the valve member. The simplicity of such revisions will be readily Vapparent. in the diagrammatic illustrations of Fig. 9. Thus the entire trainof mechanism from the introduction of the'pressure differential at the pivot 14 to the pin 83 is exactly the same as in the previous described embodiment of the invention. Moreover, the flapper valve 56 is similarly supported, but the nozzle 55 is supported on the bellows 54 so as to be disposed over the right hand end of the flapper valve 56. With this arrangement; a spring 50A is arranged to act upwardly on the right hand end of the flapper valve, thereby to urge the napper valve Il toward the nozzle B5, and the right hand end of the ilapper valve 88 is disposed beneath the pin 88, thereby reversing the relationship of the ilapper valve $8 to the pin 98 and to the nozzle Il. With the arrangement that is thus afforded. the apparatus of the present invention may be utilized where a normally closed valve is to be opened and controlled by ai? pressure to produce a constant flow through the valve.

In the previously described embodiments of the invention, the apparatus has been illustrated and described as being adapted to operate upon a linear flow scale, but the apparatus of the present invention may readily be changed so as to adapt the same for operation on a parabolic flow scale. Such an arrangement is diagrammatically illustrated in Fig. l1 of the drawings and the necessary structural revisions that are involved comprise the removal of the link 12, the lever 88,

the pivot 68 and the link 15, and different parts are substituted for the parts thus removed. Thus a bell crank lever 288, mounted on a pivot 289 that is displaced somewhat to the right of the location of the pivot 89. The bell crank 268 has an arm 288A that is so arranged that its initial position, shown in full lines in Fig. 11, is ten degrees below a horizontal line 21| passing through the pivot 269. A link 212 is connected between the pivot 14 and a pivot 213 on the end of the arm 268A, and when the pivot 1l moves from its four percent position to its one-hundred percent position, the arm 268A is moved from the initial position that is ten percent below the line 21|, through an angle of forty degrees to the dotted line position which is fifty degrees below the line 21|.

The bell crank 268 has, a second arm 268B that is so related to the arm 258A that when the arm 258A is in its initial or full line position, the arm 268B will be disposed `thirty degrees above the line 21|. Thus when the arm 288A moves through its forty degrees stroke, the arm 268B will be moved through forty degrees to the dotted line position of Fig. 11. The end of the arm 268B is connected at a pivot 216 to the lower end of a link 215 which is connected at its upper end 211 to the arm 18B of the lever 18.

The arrangement of the links and levers is such that when the arm 288B is in its full line or initial position. the arm 18A of the lever 18 will be disposed so that the pin 82 will be located so as to indicate substantially 44.72 percent along the scaie that relates to the pin 82. Thus when the arm 288B has moved to its dotted line position of y Fig. 11, the arm 18A 'will have been moved to such a position that the pin 82 is located at a onehmdred percent position along the related scale. rlhe factor that is thus derived as a fourth root function of the differential is thus introduced by the pin 82 into the calculating operation that is to be effected by the multiplying lever 85, and

the control apparatus will therefore operate according to a parabolic flow scale.

The foregoing description of the root extracting levers 68 and 268 has been confined merely to the structural characteristics and relationships thereof,.but it may be observed that both of these root extracting levers operate upon the broad principles set forth in Patent No. 2,003,839, patented June 4, 1935, on the application of Ed S. Smith, Jr. According to the method of root extraction that is explained in the aforesaid Smith p atent, use is made of versed` sine relationship which throughout a certain range of angles isl fil such as to vary substantially in accordance with the square root. Thus in the embodiment of the invention that is arranged to operate according to a linear flow scale, the differential representing element 1l and the root-extracting lever 88 are so related that when thediflerential representing element 14' moves through its complete or 100% range of movement, the link 12 will cause or allow the lever 88 to move through a range of 50 of annular movement, for it has been determined experimentally that throughout this arrangement, the versed sine of the angle between the line 1| and the arm 68A varies substantially in accordance with the square foot of the value that is represented by the position of the pivot 14.

Since the angular position of the lever arm 68A is thus representative of substantially the square root of the represented differential, it is desirable that this positional representation be transmitted to the transmitting lever 18 with the greatest possible accuracy that is consistent with simplicity of structure, and it is for this reason that the lever arm 88B is arranged to move in equal amounts above and below the horizontal line 1|, it being observed that the link 15 is substantially perpendicular to times` The lever 268 that is utilized to extract the fourth root of the differential operates substantially like the lever 68 in that the angular position thereof is representative of the square root o? the differential, but the arm 268B is so arranged with respect to the arm 268A that the arm 268B utilizes the variations in the sine relationship so as to afford a representation of the fourth root of the differential. It is for this reason that the range of movement of the arm 288B is from 30 to 70 with respect to the horizontal line 21|. Throughout this range of angular movement, the point 218, in its vertical component of movement, moves according to the sine relationship so that the vertical movements of the pivot 21B represent substantially the fourth root of the represented differential.

From the foregoing description it will be apparent that the present invention materially simplifies the application of now control apparatus to different kinds, types and designs oi' valve devices and according to the present invention the flow calculating and ilow or power controlling elements of the apparatus may be embodied in a separate or individual unit that is of such a character that it may readily be mounted on and operatively associated with any conventional tvpe of power operating valve. Under and in accordance with the present invention these advantageous results are attained in such a manner that different iiow scales may readily be utilized as may be required, and such changes in rthe character of the flow scale may be attained without material changes in the apparatus.

The iiow controller of the present invention, through the utilization of a replaceable cam in translating the valve movement of the terms of effective valve orifice is readily adaptable for quantity production because through the use of such replaceable cams the flow controlling and flow calculating unit may readily be adapted for different kinds and types and sizes of valves.

Thus, while I have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of variation and modication and I therefore do not wish to be limited to the precise details set forth,

the line 1| at all but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

l. In a flow control apparatus for association with a power operated flow control valve, a unit adapted to be mounted on the casing of sucha flow control valve, means on said unit adapted when said unit is mounted on a valve casing to be moved in accordance with the movements of the valve member of the valve, means on said unit operated by said last mentioned means and including a cam means for translating movement of said last mentioned means -into a movement which is a function of a predetermined character, means on said unit actuated by differential pressure and adapted to be actuated in accordance with the pressure differential at opposite sides of the valve opening of the valve, a settable control means on said unit adapted to govern the operationA of the power means of the power operated valve, and computing means for governing said control means and conjointly controlled in accordance with the second mentioned means and said means actuated by differential pressure.

2. In a ow control apparatus for association with a power operated flow control valve, a unit having a mounting frame adapted to be mounted on the casing of a flow control valve, means on said frame adapted when said unit is mounted on such a valve casing to be moved in accordancey with the movements of the valve member of the valve, means on said frame operated by said last mentioned means and including a cam means for translating movement of said last mentioned means into a movement which is a function of a predetermined character, differential representing means on said frame actuated by differential pressure and adapted to be actuated in accordance with the pressure differential exhibited at opposite sides of the valve opening of the valve, root extracting lever means operated by said differential representing means and operable to extract a predetermined root of the represented differential, a settable control means on said frame adapted to govern the operation of the power means of the power operated valve, and computing means mounted on said frame and governing said control means and conjointly controlled in accordance with said second mentioned means and said root extracting lever means.

3. In a'ilow control apparatus for association with a power operated flow control valve, a unit adapted to be mounted on the casing of a flow control valve, means on said unit adapted when said unit is mounted on such a valve casing to be moved in accordance with the movements of the valve member of the valve, means on said unit operated by said last mentioned means and including a cam means for translating movement of said last mentioned means into a movement which is a function of a predetermined character, differential representing means on said unit actuated by differential pressure and adapted to be moved in accordance with the pressure dierential at opposite sides of the valve opening of such valve, a further means on said unit operated by said differential representing means governing said control means and conjointly controlled in accordance with said second mentioned means and said further means. I

4. In a flow control apparatus for association with a power operated flow control valve, a unit adapted to be mounted on the casing of 'a flow control valve, means on said unit adapted when said unit is mounted on a, valve casing to be moved -in accordance with the movements of the valve member of the valve, means on said unit operated by said` last mentioned means and having operatively associated therewith for translating movement of said last mentioned means into a movement which is a function of a predetermined character, differential representing means on said unit operated by differential pressure and adapted to be actuated in accordance with the pressure differential at opposite sides of the valve opening of the valve, root extracting lever means mounted on said unit Aand operated by said differential representing means for translating movement of said differential representing means into a movement which is representative of a predetermined root of the differential, a settable control means on said unit for governing the operation of the power means of the power operated valve, a computing lever governing said control means, a shiftable support upon which said computing lever is pivoted and shifted by said cam in accordance with the movement of the moved member, and a transmitting lever of substantial length operated by said root extracting lever means and operable to rock said computing lever in accordance with the position of said root extracting lever means.

5. In a flow control apparatus for association with a power operated ow control valve, a unit Vadapted to be mounted on the casing of a iiow control valve, a lever mounted on said unit, an abutment mounted on said lever and adapted for adjustment therealong and further adapted when said unit is mounted on the valve casing to be actuated in accordance with the movements of the valve member of the valve, a translating cam mounted on said unit and actuated by said lever for translating movement of said abutment into a movement that is a function of a predetermined character, means on said unit actuated by differential pressure and adapted to be actuated in accordance with the pressure differential at opposite sides of the valve opening of the valve, a settable control means on said unit for governing the operation of the power means of the power operated valve, and computing means for governing said control means and conjointly controlled in accordance with said translatlng cam and said means actuated by differential pressure.

6. In a regulator apparatus for association with a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member shiftable with respect to said orifice to vary the effective valve orifice area and having power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve member, a control unit for the power operated actuating means of the valve comprising a frame, computing means mounted on said frame and adapted for entry therein of a first factor constituting a function of the differential of the pressures exhibited on opposite sides of the orifice of such a valve and a second factor constituting a function of the effective area i7. l of auch valve orifice, and said computing `means being operable in response to entry of such factors to compute and manifest the instantaneous flow through said valve, control means mounted on said frame for controlling the power operated means of, the valve operatively associated with member shiftable with respect to said orifice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve member, a control unit for said power operated actuating means comprising a frame, computing means mounted on said frame and adapted for entry therein of a first factor constituting a function of the differential of the pressures exhibited on opposite sides of said orifice and a second factor constituting a function of the effective area of said valve orifice, and said computing means being operable in response to entry of such factors to compute and manifest the instantaneous flow through said valve, means mounted on said frame for controlling said power operated means operatively associated with said computing means to operate said valve in accordance with the result computed by said computing means, .means including a cam operated by said valve member for entering said second factor into said computing means, and means controlled by pressures on opposite sides of said orifice for entering said first factor into said computing means.

8. In a regulator apparatus, a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member shiftable with respect to said orifice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve member, a control unit for said power operated actuating means com-v prising a frame, computing means mounted on said frame and adapted for entry therein of a first factor constituting a function of the differential of the pressures exhibited on opposite sides of said orifice and a second factor constituting a function of the effective area of said valve orlce, and said computing means being operable inresponse to entry of such factors to compute and manifest and represent the instantaneous flow through said valve, means for controlling 9. In a regulator apparatus, a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member shiftable with respect to said orice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing. and operatively connected to said valve member, a Acontrol unit for said power operated actuating means comprising a frame, a first computing lever mounted on said frame for rocking movement, a differential representing means mounted on said frame and movable along a linear path and according to a linear scale to afford a representation of the differential of the pressures exhibited on opposite sides of said orifice, a link connected` to said differential representing means and to said first computing lever and operable to rock said lever according to the versed sine relation to represent by angular movement of said lever the substantial square root of the differential represented by said` differential representing means, a second computing lever, link and lever means operated by said first computing lever and operable to introduce the square root of said differential into said second computing lever, means for introducing a second factor into said second computing lever constituting a function of the effective area of said valve orifice, and said second computing lever being operable in response to entry of such factors to compute and manifest the instantaneous flow through said valve, and means for controlling said power operated means operativelyassociated with said second computing lever to operate said valve in accordance with the result computed by said second computing lever.

10. In a flow control apparatus, a unit adapted for association with a power operated flow control valve, said unit having a mounting frame adapted to be mounted on the casing of the flow control valve, means on said frame adapted when said unit is mounted on the valve casing to be moved in accordance with the movements of the valve member of the valve,l means on said frame operated by said last mentioned means and including a translating cam for translating movement of said last mentioned means into a movement which is a function of a predetermined character, differential representing means on said frame actuated by differential pressure and adapted to be actuated in accordance with the pressure differential exhibited at opposite sides of the valve opening of such valve, root extracting lever means operated by said differential representing means and operable to extract and afford a mechanical representation of a predetermined root of the represented differential, a settable governing means on said frame for governing the operation of the power means of the power operated valve, computing means mounted on said frame and conjointly controlled in accordance with said second mentioned means and said root extracting lever means, and adjusting means for varying the effectiveness of said computing means on said governing means to thereby enable the desired constant flow to be maintained by an associated valve to be adjustably set.

11. In a regulator apparatus, a control unit adapted for association with a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member shiftable with respect to said orifice to vary the effective valve orifice area and power operated actuating means for said valve member mounted on said valve. casing and operatively connected to said valve member, said control unit comprising a frame, a first computing lever mounted on said frame for rocking movement, a differential representing means mounted on said frame actuated by differential pressure and movable along a linear path and according to a linear scale to afford a representation of the differential of the pressures exhibited on opposite sides of said orifice, a link connected to said differential representing means and to said first computing lever and operable to rock said lever according to the versed sine relation to represent by angular movement of said lever the substantial square root of the differential represented by s aid differential representing means, a second computing lever, link and lever means operated by said first computing lever and operable to rock saidsecond computing lever in accordance with the angular movement of said first computing lever, means for translating movement of the valve member into a movement that is a function of a predetermined character and operatively connected to said second computing lever for transmitting said last v mentioned movement to said second computing lever as a second factor constituting a function of the effective area of said 'valve orifice, and said second computing lever being operable when this actuated to compute and manifest the instantaneous flow through said valve, and means for controlling the power operated means of a valve and operatively associated with said second computing lever for controlling the valve in accordance the result computed by said second computing lever.

12. In a regulator apparatus, a unit adapted for association with a power operated valve having a Casing affording inlet and outlet passages with a valve orifice between said passages and a valve member shiftable with respect to said orifice to vary the effective valve orifice area, said control unit comprising a frame, computing means mounted on said frame and adapted for entry therein of a first factor constituting a function of the differential of the pressures exhibited on opposite sides of the orifice of the valve and a second factor constituting a function of the effective area of the valve orifice of the valve and said computing means being operable in response to entry of such factors to compute and manifest and represent the instantaneous flow through said valve, means for controlling the power operated means of the valve, a transmitting lever operatively connected'to said computing means and operable to transmit the representation of instantaneous flow to said controlling means in accordance with the result computed by said computing means, means adjustably supporting the transmitting lever for varying the effectiveness of said transmitting lever on said controlling means, means including a cam adapted to be operated by the valve member of the valve for entering said second factor into said computing means, and means controlled by pressures on opposite sides of the orifice for entering said first factor into said computing means.

13. In a, flow control apparatus for association with a power operated flow control valve, a unit adapted to be mounted in an operative relation with respect to a flow control valve, means on said unit adapted when said unit is mounted on such a valve casing to be moved in accordance with the movements of the valve member of the valve to afford a mechanical representation of the position of said valve member, means on said unit operated by said last mentioned means and including a translating cam means for translatins-movement of said last mentioned means into a movement which is a function of a predetermined character, differential representing means on said unit actuated by differential pressure and adapted to be actuated in accordance with the pressure differential at opposite sides of the valve opening of the valve, root extracting lever means mounted on said unit and operated by said differential representing means to extract and represent by the position thereof a predetermined root of the differential, a settable control means on said unit for governing the operation `of the'power means of the power operated valve, a computing lever. a first transmitting lever through which said computing lever is operatively associated in governing relation with said control means, a shiftable support upon which said computing lever is pivoted and shifted by said cam, a second transmitting lever operated by said root extracting lever means and operable to rock said computing lever in accordance with the position of said root extracting lever means, and means for adjusting the position of said first transmitting lever to enable the effectiveness of said first transmitting lever on said computing lever to be adjusted.

14. In a regulator apparatus, a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member having a valve stem and shiftable with respect to said orifice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve stem for operating said valve member, a control unit for said power operated actuating means comprising s a platelike frame mounted' on said valve, computing means mounted on said frame so as to be disposed on the side face of said frame that is remote from said valve and adapted for entry therein of a first factor constituting a function of the differential of the pressures exhibited on opposite sides of said orifice and a second factor constituting a function of the effective area of said valve orifice, and said computing means being operable in response to entry of .such factors to compute and manifest the instantaneous iiow through said valve, means mounted on said frame for controlling said power operated means operatively associated with said computing means to operate said valve in accordance with the result computed by said computing means, a lever mounted on the side face of said frame that is adjacent to said valve and having means thereon for entering'said second factor into said computing means, means controlled by pressures on opposite sides of said orifice for entering said first factor into said computing means, an operating bracket for said lever mounted on said valve stem and having an abutment surface thereon that is perpendicular to said valve stem, and means operatively associated with said lever and disposed in the path of said abutment surface so that said lever is actuated by said valve stem inits movements.

15. In a regulator apparatus, a valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member havingv a valve stem and shiftable with respect to said orifice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve stem for operating said valve member, a control unit for 21 said power operated actuating means comprising a plate-like frame mounted on said valve. computing means mounted on said frame so as to be disposed on the side face of said frame that is remote from said valve and adapted for entry therein of af=fl'rst factor constituting a function of the differential of the pressures exhibited on opposite sides of said orifice and a second factor constituting a function of the effective 'area of said valve orifice, and said computing means being operable in response to entry of such factors to compute and manifest the instantaneous flow through said valve, means mounted on said frame for controlling said power operated means operatively associated with said computing means to operate said valve in accordance with the result computed by said computing means, a lever mounted on the side face o! said frame that is adjacent to said valve and having a cam thereon for entering said second factor into said computing means, means controlled by pressures on opposite sides of said orifice for entering said flrst factor into said computing means, an operating bracket for said lever mounted on said valve stem and having an abutment surface thereon that is perpendicular to said valve stem. an abutment element operatively associated with said lever and disposed in the path of said abutment surface so that said lever is actuated by said valve stem in its movements, and means for adjusting said element along said lever.

16. In a regulator apparatus, a'valve having a casing affording inlet and outlet passages with a valve orifice between said passages and a valve member having a valve stem and shiftable with respect to said orifice to vary the effective valve orifice area, power operated actuating means for said valve member mounted on said valve casing and operatively connected to said valve stem for operating said valve member, a control unit for said power operated actuating means comprising a plate-like frame mounted on said valve, computing means mounted on said frame so as to be disposed on the side face of said frame that is remote from said valve and adapted for entry therein of a first factor constituting a function lof' the differential of the pressures exhibited on opposite sides of said orifice and a second factor constituting a function of the effective area of said valve orifice, and said computing means being operable in response to entry of such factors to com-pute and manifest the instantaneous flow through said valve, means mounted on said frame for controlling said power operated means operatively associated with said computing means to operate said valve in accordance with the result computed by said computing means, a lever mounted on the side face of said frame that is adjacent to said valve and having a cam thereon for entering said Vfirst factor into said computing means, means controlled by pressures on opposite sides of said orifice for entering said rst factor into said computing means, an operating bracket :for said lever mounted on said valve stem and having an abutment surface thereon that is perpendicular to said valve stem, and means operatively associated with said lever and disposed in the :path of said abutment surface so that said lever is actuated by said valve stem in its movements.

17. In a flow-calculating and power controlling unit for governing the power driven actuating means of a. valve, a plate;like frame having a rear mounting face and a front mounting face,

valve with said rear face toward the valve, a motion-translating means mounted on said rear face of said frame for actuation by and in proportion to the movements of the valve member of the valve, said motion translating means including a motion translating cam replaceably associated therewith for translating movement of the valve .member into a movement that is a function of a predetermined character, a carrier mounted on said plate for movement by said cam and including a pivot pin disposed on the forward face of said frame, a power control means mounted on the forward face of said frame and adapted for controlling the power driven actuating means of the valve, a multiplying` lever pivoted on said pivot pin and operatively associated with said power control means for governing said power control means, a differential representing means on said forward face of said frame actuated by differential pressure and adapted to be moved linearly in accordance withthe differential exhibited across the orifice of such a valve, rootextracting means mounted on the forward face of said frame and operatively associated with said differential representing means to extract a predetermined root of the represented differential, and means operated by said root extracting means to apply the resulting root to said multiplying lever.

18. In a flow control unit for governing the power driven actuating means of a valve, a platelike frame having a rear mounting face` and a front mounting face, means for securing said frame in position on a valve with said rear face toward said valve, a motion-translating means mounted on said rear face of said frame for actuation by arid in proportion to the movements of the valve member of the valve. said motion translating means including a motion translating cam replaceably associated therewith for translating movement of the valve member into a movement that is a function of a predetermined character, a carrier mounted on said plate for movement by said cam and including a pivot pin disposed on the forward face of said frame, a power control means mounted on the forward face of said frame and adapted for controlling the power driven actuating means of the valve, a multiplying lever pivoted on said pivot pin, means including a second carrier and a transmitting lever carried thereby effective to operatively associate said multiplying lever with said power control means l for governing said power control means, means operable on said second carrier to set the transmitting lever of said second carrier for different flows, a differential representing means on said forward face of ,said frame actuated by differential pressure and adapted to be moved linearly in accordance with the differential exhibited across the orifice of such a valve, root-extracting means mounted on the forward face of said frame and operatively associated with said differential representing means to extract a predetermined root of the represented differential, means operated by said root extracting means to apply the resulting root to said multiplying lever, a flrstindicating means operable by said second carrier to indicate the flow for which the mechanism is set, and a second indicating means operable by said multiplying lever to indicate the instantaneous flow.

19. In a flow-calculating and power controlling unit for governing the power driven actuating means of a valve, a frame adapted to be semeans for securing said frame in position on a cured in position on a valve, motion-translating means on said frame for actuation by the valve membel` of the valve for translating movement of the valve member into a movement that is a function of a predetermined character, a differential representing element mounted on said frame and actuated by diiferential pressure and adapted to :be moved linearly in accordance with the differential exhibited across the orifice of the valve, a root extracting bell crank lever pivotally mounted on said frame and having one arm thereof moved by said diierential representing element to utilize the versed sine relation to afford by angular positioning of said lever a representation of the square root of the diferential, said bell crank lever having a second arm the end of whichl moves along a path utilizing the sine relation to afford a representation of the square root of the square root represented by the angular position of said lever, and calculating means actuated by said second arm and said motion translating means for calculating the instantaneous ilow through the valve, and governing means controlled by said calculating means for governing the power operated actuating means of the valve. Y

20. In a now-calculating and power controlling unit for governing the power driven actuating means of a valve, a plate-like frame having a rear mounting face and a front mounting face, means for securing said frame in position on a valve with said fear face toward said valve, a motion-translating means mounted on said -rear face of said frame for actuation by and in proportion to the movements of the valve memberv of such a valve, and including cam means for translating movements of the valve member intomovement that is a function of a predetermined characten a carrier mounted onsald plate for movement by said motion-transmitting means and including a pivot pin disposed on the forward face of said frame and adapted for controlling the power driven actuating means of such a valve, a multiplying lever pivoted on said pivot pin and operatively associated with said power control means for governing said power control means, a differential representing means 0n said forward face of said frame -actuated by differential pressure and adapted to be moved linearly in accordance with the diierential exhibited across the oriee of the valve, root-extracting means mounted on the forward face of said frame and operatively associated with said differential representing means and means operated by said root extracting means to apply the resulting root to said multiplying lever.

ALFRED W. PETT.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS 

